Washington Artillery Hall, 1951. This was the second structure occupied by the Crescent City's most famous military organization. Located in the 700 block of St. Charles, the hall ran through the square all the way to Carondelet Street. For many years the School of Design used the hall for the annual Rex ball on Mardi Gras. The building was replaced in the mid-1960s by a new office building for the state of Louisiana.